Negative Carbon Emission Technologies – are they really all that sustainable?

Negative carbon emission initiatives are revered as one of the key elements in the transition to zero carbon society due to the fact that, unlike many climate policies that exist today such as carbon budgeting, they actually result in a permanent net reduction of carbon in the Earth’s atmosphere. However, in the big picture of sustainable development, are they really all that sustainable?

Bio Energy with Carbon Capture and Storage (BECCS) technologies have been cited as being a key pathway to achieving the Paris Agreement’s goal of keeping global temperature levels at <2˚C above preindustrial levels[i] and for good reasons. They would allow us to consume energy through biofuel combustion and then capture the carbon emitted from this process for injection into the Earth’s crust or chemical reaction with other elements to stabilize and store the carbon. Despite the clear benefits that this technology offers for the environment, I fear that it may be focusing too heavily upon environmental sustainability and not the other factors that constitute sustainable development.

The triple bottom line method of accounting in coevolutionary economics theory is often considered as the fundamental framework for the progression to a sustainable society. BECCS, however, does not satisfy all three pillars of this model. It threatens environmental sustainability because the fuel crops needed for biofuels would require an expansion of 7-25% of Earth’s current agricultural land use, therefore encroaching further upon primary forests and grass lands. This would threaten the societies who live in areas of fuel crop farming as local food prices would rise (researchers estimate up to an 82% increase in Africa’s food price index) and also burden their water supply and use. Furthermore, BECCS programmes would need to be rolled out on a large scale so the question of economic viability arises too, could that money be better invested elsewhere? Hence, I ask the question, is BECCS really the most sustainable solution to tackling global warming?

Other large-scale projects are under consideration such as Solar Radiation Management which aims to reduce the amount of solar radiation that enters the Earth’s atmosphere. This would reduce the warming effect that greenhouse gases have by trapping solar radiation in the atmosphere. However, this option also has its downsides as research suggests that this would have severe implications for the water cycle, especially in equatorial regions.

This therefore leaves us with the question of where do our priorities lie in the development of a sustainable society? – A set of paradoxes ensues… carbon capturing at the cost of increased land use and social degradation or reduced radiation at the expense of those living on the equator. While none of the above seem favourable, I believe that the solution is to combine the two methods so that the negative externalities of each strategy can be spread out and minimised. Fundamentally, it falls down to the leaders of these strategies to assess the negative consequences and take responsible care of all stakeholders whom they may impact.